/***************************************************************************/
/*                                                                         */
/*  afloader.c                                                             */
/*                                                                         */
/*    Auto-fitter glyph loading routines (body).                           */
/*                                                                         */
/*  Copyright 2003-2009, 2011-2012 by                                      */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include "afloader.h"
#include "afhints.h"
#include "afglobal.h"
#include "aferrors.h"


/* Initialize glyph loader. */

FT_LOCAL_DEF( FT_Error )
af_loader_init( AF_Loader loader,
                FT_Memory memory )
{
    FT_ZERO( loader );

    af_glyph_hints_init( &loader->hints, memory );
#ifdef FT_DEBUG_AUTOFIT
    _af_debug_hints = &loader->hints;
#endif
    return FT_GlyphLoader_New( memory, &loader->gloader );
}


/* Reset glyph loader and compute globals if necessary. */

FT_LOCAL_DEF( FT_Error )
af_loader_reset( AF_Loader loader,
                 FT_Face face )
{
    FT_Error error = AF_Err_Ok;


    loader->face = face;
    loader->globals = ( AF_FaceGlobals ) face->autohint.data;

    FT_GlyphLoader_Rewind( loader->gloader );

    if ( loader->globals == NULL)
    {
        error = af_face_globals_new( face, &loader->globals );
        if ( !error )
        {
            face->autohint.data =
                    ( FT_Pointer ) loader->globals;
            face->autohint.finalizer =
                    ( FT_Generic_Finalizer ) af_face_globals_free;
        }
    }

    return error;
}


/* Finalize glyph loader. */

FT_LOCAL_DEF( void )
af_loader_done( AF_Loader loader )
{
    af_glyph_hints_done( &loader->hints );

    loader->face = NULL;
    loader->globals = NULL;

#ifdef FT_DEBUG_AUTOFIT
    _af_debug_hints = NULL;
#endif
    FT_GlyphLoader_Done( loader->gloader );
    loader->gloader = NULL;
}


/* Load a single glyph component.  This routine calls itself */
/* recursively, if necessary, and does the main work of      */
/* `af_loader_load_glyph.'                                   */

static FT_Error
af_loader_load_g( AF_Loader loader,
                  AF_Scaler scaler,
                  FT_UInt glyph_index,
                  FT_Int32 load_flags,
                  FT_UInt depth )
{
    FT_Error error;
    FT_Face face = loader->face;
    FT_GlyphLoader gloader = loader->gloader;
    AF_ScriptMetrics metrics = loader->metrics;
    AF_GlyphHints hints = &loader->hints;
    FT_GlyphSlot slot = face->glyph;
    FT_Slot_Internal internal = slot->internal;
    FT_Int32 flags;


    flags = load_flags | FT_LOAD_LINEAR_DESIGN;
    error = FT_Load_Glyph( face, glyph_index, flags );
    if ( error )
    {
        goto Exit;
    }

    loader->transformed = internal->glyph_transformed;
    if ( loader->transformed )
    {
        FT_Matrix inverse;


        loader->trans_matrix = internal->glyph_matrix;
        loader->trans_delta = internal->glyph_delta;

        inverse = loader->trans_matrix;
        FT_Matrix_Invert( &inverse );
        FT_Vector_Transform( &loader->trans_delta, &inverse );
    }

    switch ( slot->format )
    {
        case FT_GLYPH_FORMAT_OUTLINE:
            /* translate the loaded glyph when an internal transform is needed */
            if ( loader->transformed )
            {
                FT_Outline_Translate( &slot->outline,
                                      loader->trans_delta.x,
                                      loader->trans_delta.y );
            }

            /* copy the outline points in the loader's current               */
            /* extra points which is used to keep original glyph coordinates */
            error = FT_GLYPHLOADER_CHECK_POINTS( gloader,
                                                 slot->outline.n_points + 4,
                                                 slot->outline.n_contours );
            if ( error )
            {
                goto Exit;
            }

            FT_ARRAY_COPY( gloader->current.outline.points,
                           slot->outline.points,
                           slot->outline.n_points );

            FT_ARRAY_COPY( gloader->current.outline.contours,
                           slot->outline.contours,
                           slot->outline.n_contours );

            FT_ARRAY_COPY( gloader->current.outline.tags,
                           slot->outline.tags,
                           slot->outline.n_points );

            gloader->current.outline.n_points = slot->outline.n_points;
            gloader->current.outline.n_contours = slot->outline.n_contours;

            /* compute original horizontal phantom points (and ignore */
            /* vertical ones)                                         */
            loader->pp1.x = hints->x_delta;
            loader->pp1.y = hints->y_delta;
            loader->pp2.x = FT_MulFix( slot->metrics.horiAdvance,
                                       hints->x_scale ) + hints->x_delta;
            loader->pp2.y = hints->y_delta;

            /* be sure to check for spacing glyphs */
            if ( slot->outline.n_points == 0 )
            {
                goto Hint_Metrics;
            }

            /* now load the slot image into the auto-outline and run the */
            /* automatic hinting process                                 */
            if ( metrics->clazz->script_hints_apply )
            {
                metrics->clazz->script_hints_apply( hints,
                                                    &gloader->current.outline,
                                                    metrics );
            }

            /* we now need to adjust the metrics according to the change in */
            /* width/positioning that occurred during the hinting process   */
            if ( scaler->render_mode != FT_RENDER_MODE_LIGHT )
            {
                FT_Pos old_rsb, old_lsb, new_lsb;
                FT_Pos pp1x_uh, pp2x_uh;
                AF_AxisHints axis = &hints->axis[ AF_DIMENSION_HORZ ];
                AF_Edge edge1 = axis->edges;         /* leftmost edge  */
                AF_Edge edge2 = edge1 +
                                axis->num_edges - 1; /* rightmost edge */


                if ( axis->num_edges > 1 && AF_HINTS_DO_ADVANCE( hints ))
                {
                    old_rsb = loader->pp2.x - edge2->opos;
                    old_lsb = edge1->opos;
                    new_lsb = edge1->pos;

                    /* remember unhinted values to later account */
                    /* for rounding errors                       */

                    pp1x_uh = new_lsb - old_lsb;
                    pp2x_uh = edge2->pos + old_rsb;

                    /* prefer too much space over too little space */
                    /* for very small sizes                        */

                    if ( old_lsb < 24 )
                    {
                        pp1x_uh -= 8;
                    }

                    if ( old_rsb < 24 )
                    {
                        pp2x_uh += 8;
                    }

                    loader->pp1.x = FT_PIX_ROUND( pp1x_uh );
                    loader->pp2.x = FT_PIX_ROUND( pp2x_uh );

                    if ( loader->pp1.x >= new_lsb && old_lsb > 0 )
                    {
                        loader->pp1.x -= 64;
                    }

                    if ( loader->pp2.x <= edge2->pos && old_rsb > 0 )
                    {
                        loader->pp2.x += 64;
                    }

                    slot->lsb_delta = loader->pp1.x - pp1x_uh;
                    slot->rsb_delta = loader->pp2.x - pp2x_uh;
                }
                else
                {
                    FT_Pos pp1x = loader->pp1.x;
                    FT_Pos pp2x = loader->pp2.x;


                    loader->pp1.x = FT_PIX_ROUND( pp1x );
                    loader->pp2.x = FT_PIX_ROUND( pp2x );

                    slot->lsb_delta = loader->pp1.x - pp1x;
                    slot->rsb_delta = loader->pp2.x - pp2x;
                }
            }
            else
            {
                FT_Pos pp1x = loader->pp1.x;
                FT_Pos pp2x = loader->pp2.x;


                loader->pp1.x = FT_PIX_ROUND( pp1x + hints->xmin_delta );
                loader->pp2.x = FT_PIX_ROUND( pp2x + hints->xmax_delta );

                slot->lsb_delta = loader->pp1.x - pp1x;
                slot->rsb_delta = loader->pp2.x - pp2x;
            }

            /* good, we simply add the glyph to our loader's base */
            FT_GlyphLoader_Add( gloader );
            break;

        case FT_GLYPH_FORMAT_COMPOSITE:
        {
            FT_UInt nn, num_subglyphs = slot->num_subglyphs;
            FT_UInt num_base_subgs, start_point;
            FT_SubGlyph subglyph;


            start_point = gloader->base.outline.n_points;

            /* first of all, copy the subglyph descriptors in the glyph loader */
            error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs );
            if ( error )
            {
                goto Exit;
            }

            FT_ARRAY_COPY( gloader->current.subglyphs,
                           slot->subglyphs,
                           num_subglyphs );

            gloader->current.num_subglyphs = num_subglyphs;
            num_base_subgs = gloader->base.num_subglyphs;

            /* now read each subglyph independently */
            for ( nn = 0; nn < num_subglyphs; nn++ )
            {
                FT_Vector pp1, pp2;
                FT_Pos x, y;
                FT_UInt num_points, num_new_points, num_base_points;


                /* gloader.current.subglyphs can change during glyph loading due */
                /* to re-allocation -- we must recompute the current subglyph on */
                /* each iteration                                                */
                subglyph = gloader->base.subglyphs + num_base_subgs + nn;

                pp1 = loader->pp1;
                pp2 = loader->pp2;

                num_base_points = gloader->base.outline.n_points;

                error = af_loader_load_g( loader, scaler, subglyph->index,
                                          load_flags, depth + 1 );
                if ( error )
                {
                    goto Exit;
                }

                /* recompute subglyph pointer */
                subglyph = gloader->base.subglyphs + num_base_subgs + nn;

                if ( subglyph->flags & FT_SUBGLYPH_FLAG_USE_MY_METRICS )
                {
                    pp1 = loader->pp1;
                    pp2 = loader->pp2;
                }
                else
                {
                    loader->pp1 = pp1;
                    loader->pp2 = pp2;
                }

                num_points = gloader->base.outline.n_points;
                num_new_points = num_points - num_base_points;

                /* now perform the transformation required for this subglyph */

                if ( subglyph->flags & ( FT_SUBGLYPH_FLAG_SCALE |
                                         FT_SUBGLYPH_FLAG_XY_SCALE |
                                         FT_SUBGLYPH_FLAG_2X2 ))
                {
                    FT_Vector *cur = gloader->base.outline.points +
                                     num_base_points;
                    FT_Vector *limit = cur + num_new_points;


                    for ( ; cur < limit; cur++ )
                    {
                        FT_Vector_Transform( cur, &subglyph->transform );
                    }
                }

                /* apply offset */

                if ( !( subglyph->flags & FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES ))
                {
                    FT_Int k = subglyph->arg1;
                    FT_UInt l = subglyph->arg2;
                    FT_Vector *p1;
                    FT_Vector *p2;


                    if ( start_point + k >= num_base_points ||
                         l >= ( FT_UInt ) num_new_points )
                    {
                        error = AF_Err_Invalid_Composite;
                        goto Exit;
                    }

                    l += num_base_points;

                    /* for now, only use the current point coordinates;    */
                    /* we may consider another approach in the near future */
                    p1 = gloader->base.outline.points + start_point + k;
                    p2 = gloader->base.outline.points + start_point + l;

                    x = p1->x - p2->x;
                    y = p1->y - p2->y;
                }
                else
                {
                    x = FT_MulFix( subglyph->arg1, hints->x_scale ) + hints->x_delta;
                    y = FT_MulFix( subglyph->arg2, hints->y_scale ) + hints->y_delta;

                    x = FT_PIX_ROUND( x );
                    y = FT_PIX_ROUND( y );
                }

                {
                    FT_Outline dummy = gloader->base.outline;


                    dummy.points += num_base_points;
                    dummy.n_points = ( short ) num_new_points;

                    FT_Outline_Translate( &dummy, x, y );
                }
            }
        }
            break;

        default:
            /* we don't support other formats (yet?) */
            error = AF_Err_Unimplemented_Feature;
    }

    Hint_Metrics:
    if ( depth == 0 )
    {
        FT_BBox bbox;
        FT_Vector vvector;


        vvector.x = slot->metrics.vertBearingX - slot->metrics.horiBearingX;
        vvector.y = slot->metrics.vertBearingY - slot->metrics.horiBearingY;
        vvector.x = FT_MulFix( vvector.x, metrics->scaler.x_scale );
        vvector.y = FT_MulFix( vvector.y, metrics->scaler.y_scale );

        /* transform the hinted outline if needed */
        if ( loader->transformed )
        {
            FT_Outline_Transform( &gloader->base.outline, &loader->trans_matrix );
            FT_Vector_Transform( &vvector, &loader->trans_matrix );
        }
#if 1
        /* we must translate our final outline by -pp1.x and compute */
        /* the new metrics                                           */
        if ( loader->pp1.x )
        {
            FT_Outline_Translate( &gloader->base.outline, -loader->pp1.x, 0 );
        }
#endif
        FT_Outline_Get_CBox( &gloader->base.outline, &bbox );

        bbox.xMin = FT_PIX_FLOOR( bbox.xMin );
        bbox.yMin = FT_PIX_FLOOR( bbox.yMin );
        bbox.xMax = FT_PIX_CEIL( bbox.xMax );
        bbox.yMax = FT_PIX_CEIL( bbox.yMax );

        slot->metrics.width = bbox.xMax - bbox.xMin;
        slot->metrics.height = bbox.yMax - bbox.yMin;
        slot->metrics.horiBearingX = bbox.xMin;
        slot->metrics.horiBearingY = bbox.yMax;

        slot->metrics.vertBearingX = FT_PIX_FLOOR( bbox.xMin + vvector.x );
        slot->metrics.vertBearingY = FT_PIX_FLOOR( bbox.yMax + vvector.y );

        /* for mono-width fonts (like Andale, Courier, etc.) we need */
        /* to keep the original rounded advance width; ditto for     */
        /* digits if all have the same advance width                 */
#if 0
        if ( !FT_IS_FIXED_WIDTH( slot->face ) )
          slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
        else
          slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
                                                 x_scale );
#else
        if ( scaler->render_mode != FT_RENDER_MODE_LIGHT &&
             (FT_IS_FIXED_WIDTH( slot->face ) ||
              ( af_face_globals_is_digit( loader->globals, glyph_index ) &&
                metrics->digits_have_same_width )))
        {
            slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
                                                   metrics->scaler.x_scale );

            /* Set delta values to 0.  Otherwise code that uses them is */
            /* going to ruin the fixed advance width.                   */
            slot->lsb_delta = 0;
            slot->rsb_delta = 0;
        }
        else
        {
            /* non-spacing glyphs must stay as-is */
            if ( slot->metrics.horiAdvance )
            {
                slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
            }
        }
#endif

        slot->metrics.vertAdvance = FT_MulFix( slot->metrics.vertAdvance,
                                               metrics->scaler.y_scale );

        slot->metrics.horiAdvance = FT_PIX_ROUND( slot->metrics.horiAdvance );
        slot->metrics.vertAdvance = FT_PIX_ROUND( slot->metrics.vertAdvance );

        /* now copy outline into glyph slot */
        FT_GlyphLoader_Rewind( internal->loader );
        error = FT_GlyphLoader_CopyPoints( internal->loader, gloader );
        if ( error )
        {
            goto Exit;
        }

        /* reassign all outline fields except flags to protect them */
        slot->outline.n_contours = internal->loader->base.outline.n_contours;
        slot->outline.n_points = internal->loader->base.outline.n_points;
        slot->outline.points = internal->loader->base.outline.points;
        slot->outline.tags = internal->loader->base.outline.tags;
        slot->outline.contours = internal->loader->base.outline.contours;

        slot->format = FT_GLYPH_FORMAT_OUTLINE;
    }

    Exit:
    return error;
}


/* Load a glyph. */

FT_LOCAL_DEF( FT_Error )
af_loader_load_glyph( AF_Loader loader,
                      FT_Face face,
                      FT_UInt gindex,
                      FT_Int32 load_flags )
{
    FT_Error error;
    FT_Size size = face->size;
    AF_ScalerRec scaler;


    if ( !size )
    {
        return AF_Err_Invalid_Argument;
    }

    FT_ZERO( &scaler );

    scaler.face = face;
    scaler.x_scale = size->metrics.x_scale;
    scaler.x_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */
    scaler.y_scale = size->metrics.y_scale;
    scaler.y_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */

    scaler.render_mode = FT_LOAD_TARGET_MODE( load_flags );
    scaler.flags = 0;  /* XXX: fix this */

    error = af_loader_reset( loader, face );
    if ( !error )
    {
        AF_ScriptMetrics metrics;
        FT_UInt options = 0;


#ifdef FT_OPTION_AUTOFIT2
        /* XXX: undocumented hook to activate the latin2 hinter */
        if ( load_flags & ( 1UL << 20 ) )
          options = 2;
#endif

        error = af_face_globals_get_metrics( loader->globals, gindex,
                                             options, &metrics );
        if ( !error )
        {
            loader->metrics = metrics;

            if ( metrics->clazz->script_metrics_scale )
            {
                metrics->clazz->script_metrics_scale( metrics, &scaler );
            }
            else
            {
                metrics->scaler = scaler;
            }

            load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_IGNORE_TRANSFORM;
            load_flags &= ~FT_LOAD_RENDER;

            if ( metrics->clazz->script_hints_init )
            {
                error = metrics->clazz->script_hints_init( &loader->hints,
                                                           metrics );
                if ( error )
                {
                    goto Exit;
                }
            }

            error = af_loader_load_g( loader, &scaler, gindex, load_flags, 0 );
        }
    }
    Exit:
    return error;
}


/* END */
